1. Field of the Invention
The present invention relates to a data processing apparatus having a recording medium to which data can be recorded, and more particularly, to an authentication method according to which recording data to and restoring data from an authenticated recording device is performed.
2. Description of the Related Art
Video signal reception apparatuses having a recording medium to which a video signal can be stored include: a set-top box having a hard disc drive (HDD), a CD recording device, or a DVD recording device, a personal video recorder (PVR), a monitor, a personal computer (PC), and a VCR.
A set-top box is usually used in video on demand (VOD) services, which enable a user to watch a desired program any time by directly selecting contents stored in a media database (MDB), unlike the unilateral method by which the present broadcasting stations deliver programs to viewers. The basic system for this VOD service comprises a video source system (VSS), which has a mounted video server apparatus, a set-top box, which is the user terminal apparatus, and network equipment.
FIG. 1 is a schematic diagram of a general structure of a VOD service.
The system for the VOD service comprises: MDB 102, a video server 104, a backbone communications network 106, subscriber networks 108, and a set-top box 110.
The video server 104 performs functions including, reception, handling, and management of user requests, storing large amount of digital video data, multiple I/O functions, database management functions, and fault recovery.
The set-top box (STB) 110 performs functions, such as, connection of subscriber networks and users, restoring video data from compressed data, and security and reservation functions.
Korean Laid-Open Patent Application No. 1997-4852 (laid open Jan. 29, 1997) discusses a set-top box capable of storing VOD service data. Accordingly, VOD service data provided by a service provider is stored in an HDD, and after connection to the provider is terminated, the VOD service data stored in the HDD can be reproduced at a desired time.
FIG. 2 is a schematic diagram of an exemplary set-top box having an HDD.
The set-top box shown in FIG. 2 comprises: a system controller 204, which controls the operation of the set-top box 200 according to a user control command received through a remote controller reception unit 202, an interface 206 which interfaces the video server 104 shown in FIG. 1 via control of the system controller 204, an MPEG decoder 208 which decodes the data compressed in compliance with the MPEG format and transmitted by the video server 104 to restore video and voice data, a digital-to-analog (D/A) conversion unit 210 which converts the video and voice data reproduced by the MPEG decoder 208 into an analog signal so that the data can be output through a TV or a monitor, and an HDD 212 which stores the MPEG compressed data and transmitted by the video server 104 or reproduces the stored MPEG compressed data and provides to the MPEG decoder 208.
The apparatus shown in FIG. 2 stores the VOD service data provided by the video server 104, and after the connection to the video server 104 is terminated, enables the VOD service to allow data stored in the HDD to be reproduced by a user.
Korean Laid-Open Patent Application No. 2002-71268 (laid open Sep. 12, 2002) discusses an apparatus and method to prevent illegal use of VOD services. Accordingly, illegal access and unauthorized use by non-subscriber users of VOD service data provided to paid subscribers can be prevented.
FIG. 3 is a diagram of the structure of an apparatus to prevent illegal use disclosed in Korean Laid-Open Patent Application No. 2002-71268. The apparatus shown in FIG. 3 comprises: a user authentication unit 302, a control apparatus unit 304, a media server connection unit 306, a database 308, and an input apparatus unit 310. The control apparatus unit 304 cuts off the path between the media server connection unit 306 and the input apparatus unit 310 according to the authentication result of the user authentication unit 302.
However, although unauthorized use by non-subscriber users can be prevented according to the invention of Korean Laid-Open Patent Application No. 2002-71268, impermissible use of legally received VOD service data through a permissible path cannot be prevented.
More specifically, if the HDD 212 can be separated from the set-top box or replaced by another in the apparatus shown in FIG. 1, the VOD service data stored in the HDD can be used for other purposes than the permissible viewing.
In some VOD services, the VOD service data stored in the HDD 212 is maintained over a predetermined period and automatically deleted so that illegal use of the contents can be prevented. However, even via this method, the VOD contents cannot be protected in case of separation of the HDD from the set-top box or replacement of the same by another.